Project Summary/Abstract The combined MD-PhD program at Columbia University's College of Physicians and Surgeons in New York City is designed to train Physician-Scientists who will become the next generation of leaders in medical research. The growing complexity of both medicine and science has made it increasingly challenging to sustain a pipeline of Physician-Scientists. The Columbia Medical Scientist Training Program (MSTP) is providing outstanding training and mentorship, thereby supporting this important national mission. The MSTP at Columbia is embedded in rigorous, intellectual, and interactive environment. Trainees undertake a modern 18-month preclinical medical curriculum followed by two clinical rotations, PhD thesis research for 3 to 4 years and finally another large block of clinical rotations. During the preclinical training, students are engaged in graduate courses and lab rotations. During thesis research they further develop clinical skills. Upon completion of the 7 to 8 year program, the trainees emerge as rigorous, mature, young scientists who are also exceptional clinicians. The trainee cohort has outstanding credentials. The program's leadership has decades of experience in graduate and medical education. Students are trained by world-class mentors in medicine and science and thereby learn to play a key role in the discovery of important new scientific knowledge and the translation of scientific findings to clinical practice.